[3/3 blink] Support redirect option of Request and "opaqueredirect" response type.

LayoutTests/http/tests/fetch/script-tests/request.js

 if (self.importScripts) {
   importScripts('../resources/fetch-test-helpers.js');
 }
 
 var URL = 'https://www.example.com/test.html';
 
 test(function() {
     var headers = new Headers;
     headers.set('User-Agent', 'Mozilla/5.0');
     headers.set('Accept', 'text/html');
@@ skipping 204 matching lines @@
             }
             request2 = new Request(request1, init2);
             assert_equals(request2.credentials,
                           credentials2 ? credentials2 : request1.credentials,
                           'Request.credentials should be overridden');
           });
       });
   }, 'Request credentials test');
 
 test(function() {
+    var request1 = {};
+    var request2 = {};
+    var REDIRECTS = ['follow', 'error', 'manual', '', undefined];
+    REDIRECTS.forEach(function(redirect1) {
+        var init1 = {};
+        if (redirect1 != undefined) { init1['redirect'] = redirect1; }
+        request1 = new Request(URL, init1);
+        assert_equals(request1.redirect, redirect1 || 'follow',
+                      'Request.redirect should match');
+        request1 = new Request(request1);
+        assert_equals(request1.redirect, redirect1 || 'follow',
+                      'Request.redirect should match');
+        REDIRECTS.forEach(function(redirect2) {
+            request1 = new Request(URL, init1);
+            var init2 = {};
+            if (redirect2 != undefined) {
+              init2['redirect'] = redirect2;
+            }
+            request2 = new Request(request1, init2);
+            assert_equals(request2.redirect,
+                          redirect2 ? redirect2 : request1.redirect,
+                          'Request.redirect should be overridden');
+          });
+      });
+  }, 'Request redirect test');
+
+test(function() {
     ['same-origin', 'cors', 'no-cors'].forEach(function(mode) {
         FORBIDDEN_METHODS.forEach(function(method) {
             assert_throws(
               {name: 'TypeError'},
               function() {
                 var request = new Request(URL, {mode: mode, method: method});
               },
               'new Request with a forbidden method (' + method + ') should ' +
               'throw');
           });
@@ skipping 376 matching lines @@
 
 // Tests for requests context.
 test(function() {
     var request = new Request('http://localhost/', {method: 'POST', body: ''});
     assert_equals(request.context, '',
                   'Request.context should be empty string ' +
                   'for synthetic Request object');
   }, 'RequestContext of a synthetic Request object');
 
 done();